Because of the biocompatibility of poly(alkyleneglycols), also known as polyalkyl ethers or poly(alkylene oxide), poly(oxyalkylene)-containing polymers can find use in various fields, in particular in biomedical fields, such as, for example, carriers for drug-delivery, artificial tissues, dentrifices, contact lenses, intraocular lenses, and other biomedical devices. However, poly(oxyalkylene)-containing polymers may be susceptible to oxidative degradation and high-temperature-induced or autoclave-induced haziness. Oxidative degradation may cause changes in the properties of an article made from the poly(oxyalkylene)-containing polymers. Autoclave-induced haziness may adversely affect the optical properties of an ophthalmic device, such as, a contact lens or an intraocular lens made of a poly(oxyalkylene)-containing material. Those susceptibilities may limit the applications of poly(oxyalkylene)-containing polymers, in particular, in making ophthalmic devices.
U.S. Patent Application Publication No. 2004/0116564A1 describes a method for stabilizing poly(oxyalkylene)-containing materials. By using such method, a poly(oxyalkylene)-containing polymeric material can be stabilized so that oxidative degradation is significantly reduced. As such, a poly(oxyalkylene)-containing polymeric material can have increased applications, especially in the biomedical field. But, a poly(oxyalkylene)-containing material still may not be suitable for making ophthalmic devices, because ophthalmic devices must be sterilized, typically by autoclave. Autoclave-induced haziness may affect adversely the optical properties of the ophthalmic devices and thereby their primary function in correcting vision deficiencies.
Accordingly, there is still a need for a method for reducing or eliminating the susceptibility to autoclave-induced haziness of poly(oxyalkylene)-containing polymeric materials.